With increased worldwide demand for telecommunications and networking services and the requisite bandwidth, there has been a continuing and growing need to lay cables and conduit, especially for fiber-optic cables. The rights-of-way along railroad tracks provide existing paths for installation of thousands of kilometers of new cable. Railway track-maintenance equipment for maintaining railroad track rights of way has been known for many years. Cable-laying apparatus including rail plows for plowing a trench alongside railroad tracks has also been known and has been used for laying cable.
U.S. Pat. No. 3,546,887 to Hehnus disclosed an apparatus for burying lineal material adjacent to railroad tracks, utilizing a track-supported mobile base. Rearwardly trailed, elongate beams extend laterally in a positionable manner from a railroad car side and draw a blade element through the ground to form a kerf within which continuous flexible material such as signal or electrical cable is deposited by a cable shoe carried by the blade. Hydraulic components position the beam to adjustably locate the blade for depositing the cable at selected depths and distances from the railroad tracks.
U.S. Pat. No. 3,815,268 to Yard disclosed a ballast regulator control means for controlling the ballast box of a ballast regulator used for positioning or "regulating" ballast on the shoulder of a railroad track. Hydraulic cylinders are provided for adjusting the position of the ballast box around two respective pivotal axes. A cable attached to the outer end of the arm coupled to hoisting means on the vehicle chassis controls the height of the arm.
U.S. Pat. No. 4,038,828 to Schuck et al. disclosed a vertical lift and tilt control for plows for laying cable, pipe and the like underground. A mast assembly has a generally vertical rail, and a slide frame is slidably mounted on the vertical rail. The plow assembly is supported on the slide frame and a power means, such as a piston, is connected to the mast and slide frames for raising and lowering the plow assembly. The mast assembly is pivotally supported on a suitable vehicle and a second power means, such as a piston, is pivotally connected to the vehicle and the mast assembly for adjusting the tilt or attack angle of the plow blade.
U.S. Pat. No. 4,040,261 to Schuck et al. disclosed a vibratory plow suitable for laying cable, pipe and the like underground. The plow blade is pivotally mounted on a frame assembly on a resilient mounting. The frame assembly includes a U-shaped yoke pivotally mounted at opposite ends to the frame assembly. A vibrator is mounted on the yoke and the yoke is pivotally connected to the blade by a link which is pivotally connected at opposed ends to the blade and the yoke. The blade is thereby vibrated in an orbital plowing motion as the blade is drawn through the earth by a suitable vehicle.
U.S. Pat. No. 4,119,157 to Schuck et al. disclosed a control mechanism for adjusting the angle and lateral position of a plow blade which is particularly useful for laying cable, pipe and the like underground. The control mechanism includes a fixed frame, which is supported on a suitable vehicle and a slide frame, which supports the plow blade. The slide frame is slidably supported on a horizontal rail of the fixed frame. A piston or other power means is connected to the fixed and slide frames to adjust the lateral position of the supported plow blade. The plow includes a support frame which is pivotally mounted on a vertical pivot on a slide frame, and the control mechanism includes means to angularly adjust the blade on the pivot.
U.S. Pat. No. 4,720,929 to Umberson disclosed a trenching device in which an improved torsional limiting device and associated control system provide for protection of the equipment components in the event the cutting wheel encounters unforeseen obstructions.
U.S. Pat. No. 4,768,297 to Rivard disclosed a trenching wheel, especially for digging trenches. Tools are mounted on ring portions removably fixed to the periphery of the wheel.
U.S. Pat. No. 4,784,524 to Stine disclosed apparatus for holding the plow blade of a railroad car-mounted cable laying device which includes support means on the railroad car for supporting the plow blade and stop means on the support means for prohibiting the plow blade from sliding off the support means. When more than one plow blade is provided, tethering means is also provided between the plow blades for constraining the plow blades and prohibiting the plow blades from sliding off the support means.
U.S. Pat. No. 4,794,709 to Rivard disclosed a device for digging trenches, including at least one digging wheel with a wheel framework which is connected to a vehicle by means of a mobile carriage for lowering or raising the digging wheel, means for causing the digging wheel to pivot about a first pivoting axis, and means for causing the digging wheel to pivot about a second pivoting axis.
U.S. Pat. No. 4,871,127 to Clark, reissued as RE34488, disclosed a portable device for storing an endless metallic or fiber-optic cable. A portable trailer supports a long horizontal tube on which is mounted a rotatable and reciprocable drum and a fixed storage reel. Rotating and reciprocating the drum neatly winds the cable onto the storage reel from a supply reel, although there is no access to the cable ends.
U.S. Pat. No. 4,890,958 to Dancer disclosed a railroad right-of-way cable/pipe trench-plowing machine which includes a locomotive, standard flat car, a hydraulic boomed vehicle such as a backhoe attached to the flat car, a steerable plowing blade attached to the hydraulic boom, and a cable attached at one end to the plowing blade and the other end to the locomotive. The plowing blade is pivotally attached to the hydraulic boom and has a tooth located at its bottom end foot, which is disposed to point in the direction to be trenched. A cable guide, consisting of a J-shaped tube, is attached to the trailing edge of the vertical blade and is disposed such that a utility cable fed into the top end of the cable guide is automatically directed to the base of the trench. An optional feature provides a hydraulic ram attached between the pivoting blade and the hydraulic boom for hydraulically pivoting the blade about the boom. The hydraulic ram provides additional steering capabilities.
U.S. Pat. No. 5,482,121 to Draney et al. disclosed a vibratory cable plow assembly including a frame assembly for connecting a plow blade to a frame of a prime mover. The frame assembly supports a vibrating mechanism or shaker that is adapted to impart vibratory movements to the plow blade. A lower support mounts a blade supporting frame for rocking movement around a generally horizontal pivot mechanism. The vibratory mechanism is mounted on the blade supporting frame.
U.S. Pat. No. 5,490,339 to Accettola disclosed a center-line trenching system for earth surface use, as on paved streets, roads, highways and the like. The system includes a rubber-tired drive machine for advancing a side-by-side tandem of a earth saw and a conveyor attached to a rear surface of the drive machine.
U.S. Pat. No. 5,558,465 to Pecot et al. disclosed a method and device for laying an underground telecommunications cable. A first drum is positioned stationarily and supplies the cable to a trench that is dug in the ground. A hauling pig is connected to the leading end of the cable. A second drum, mounted to a movable tractor, supplies a tube to the trench and is intended to receive the cable. The tractor also has a plowshare mounted to its forward end for forming the trench as the tractor moves. A compressor, connected to a tube section rearwardly of the pig, propels the leading end of the cable to a predetermined point in a turn of a rolled tube as stored on the second drum. In the event an obstacle is encountered by the tractor, the compressor is interrupted and a length of tube is payed out from the second drum and temporarily remains unoccupied by cable. The payed out length of tube is cut at an end so that the tractor becomes free to move around the obstacle.
U.S. Pat. No. 5,596,822 to Desmarais et al. disclosed a rubber-tired cable-laying apparatus for burying cable in or adjacent to a railway bed. A cable-laying plough is mounted to a rubber-tired loader, and the loader moves forward under its own power while straddling the track. A pair of rail wheels are mounted on the forward and rearward ends of the loader.
The apparatus and methods known for laying cables, pipes, and conduits have no doubt performed well in their intended uses. However, considerations of speed and efficiency have required an improved apparatus for laying cable in railroad rights-of-way, alongside the railroad tracks.